Tools for clamping and aligning boiler tubes when connecting the ends of the boiler tubes by welding are known as disclosed in U.S. Pat. Nos. 4,493,139, 4,579,272 and 4,722,468. The devices disclosed in the above-mentioned patents include structures for securing boiler tube ends in aligned and adjacent relation and function effectively when the boiler tubes are in spaced relation. However, in boiler wall tubes, the boiler tubes are positioned in closely spaced relation and are interconnected by webs to form a continuous boiler tube sheet or wall. The tools disclosed in the above-mentioned patents are not especially adapted for use with boiler tubes forming a boiler wall.
In addition, and considered relevant to the present invention, are U.S. Pat. Nos. 4,846,391 and 4,936,500, both issued to Gary McClure, disclosing various embodiments of boiler wall tube tools that clampingly engage the respective tubes to facilitate welding in the repair of a wall tube or tubes. The '391 patent discloses a boiler wall tube tool having a pair of opposed clamp members that includes a pair of recesses to engage adjacent ends of a pair of boiler wall tubes on opposite sides of a juncture between adjacent ends. The tool includes means for moving the clamps toward one another, thereby generating a secure clamp engagement between the clamps onto the respective tube or tubes. Moving means is described as a handle and a mounting bar that is inserted through each of the clamps. The '500 patent is a variation of the '391 patent is some respects, and specifically discloses a boiler wall tube tool that is bolted directly onto the boiler tube wall as opposed to utilizing a handle and mounting bar combination disclosed in '391. However, neither of the Gary McClure patents demonstrate an ability to provide versatility to the user in accommodating varying sizes beyond the dimensions of the recesses provided in the '391 and '500 disclosures. The present invention overcomes this deficiency by providing the user with the ability to use the present invention on variously sized/dimensioned tubes.
Other prior art considered relevant to the present invention includes U.S. Pat. No. 5,481,793 (also issued to Gary McClure), U.S. Pat. No. 2,612,821 (issued to Skay), 6,007,029 (issued to Barringer et al.), U.S. Pat. No. 5,083,372 (issued to Polutnik), U.S. Pat. No. 5,044,075 (issued to Brennan et al.), U.S. Pat. No. 4,979,294 (issued to Bowman et al.), U.S. Pat. No. 6,308,921 (issued to Borzucki), and the group of U.S. Pat. Nos. 5,893,209, 5,974,642, 6,182,354 and U.S. Pat. No. 6,385,841 (all issued to Weeks).